| 摘要 |
<p>In a four color liquid crystal light valve image projector employing first (20) and second (22) liquid crystal light valves, the improvement is characterized by a unitary prepolarizing prism assembly (10) which provides a combined beam of light having a first component of a first color (R) and first polarization state (S) and a second component of a second color (G) and a second polarization state (P) and a main polarizing prism (18) which couples light of said first color (R) and said first polarization state (S) to one of said two liquid crystal light valves (22) and light of said second color (G) and a second polarization state (P) to the other of said light valves (20). The unitary prepolarizing assembly (10) includes: a first color filter (12) for reflecting, from an input beam of unpolarized white light, light of a third color (B) and transmitting light of first (R) and second (G) colors in a combined beam; a first prepolarizer (14) mounted on said first filter (12) for removing, from said combined beam, light of said second color (G) and said first polarization state (S); and a second prepolarizer (16) mounted on said first prepolarizer (14) for removing, from said combined beam, light of said first color (R) and said second polarization state (P). A four color liquid crystal light valve image projector employing a single liquid crystal light valve (50) is also disclosed where a liquid crystal switch (30) is disposed between the unitary prepolarizing prism assembly (10) and the main polarizing prism (18) for interchanging the plarization states of the light in the combined beam.</p> |
